Processing device, ultrasonic device, ultrasonic probe, and ultrasonic diagnostic device

ABSTRACT

An ultrasonic device includes a substrate, first ultrasonic elements having a resonance characteristic of a first frequency, and second ultrasonic elements having a resonance characteristic of a second frequency lower than the first frequency. The first ultrasonic elements are arranged along a first direction to make a first to an n-th high-frequency ultrasonic element lines. The second ultrasonic elements are arranged along the first direction to make a first to an n-th low-frequency ultrasonic element lines. The first to the n-th high-frequency ultrasonic element lines and the first to the n-th low-frequency ultrasonic element lines are arranged along a second direction. The first and second ultrasonic elements have an opening, a vibrating membrane, and a piezo element part. A length in the second direction of the opening of the first ultrasonic element is shorter than a length in the second direction of the opening of the second ultrasonic element.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 13/903,518 filed on May 28, 2013, which claims priority toJapanese Patent Application No. 2012-121889 filed on May 29, 2012. Theentire disclosures of U.S. patent application Ser. No. 13/903,518 andJapanese Patent Application No. 2012-121889 are hereby incorporatedherein by reference.

BACKGROUND

Technical Field

The present invention relates to an ultrasonic device, an ultrasonicprobe, and an ultrasonic diagnostic device.

Related Art

As devices that irradiate an ultrasonic wave toward an object andreceive a reflected wave from interfaces having different acousticimpedance in an internal object, for example, ultrasonic diagnosticapparatuses for inspecting the inside of the human body are well known.As ultrasonic devices (ultrasonic probes) used for ultrasonic diagnosticdevices, for example, Patent Document 1 discloses a matrix array patternarrangement of piezo elements and a method for outputting an ultrasonicwave.

Japanese Laid-open Patent Publication No. 2006-61252 (Patent Document 1)is an example of the related art.

SUMMARY Problems to be Solved by the Invention

However, in this method, a driving signal cannot be changed in responseto a distance between an ultrasonic probe and an object so that thereduction of the resolution occurs depending on a distance to an object.Therefore, a plurality of ultrasonic probes is used properly in responseto a distance to an object. According to some aspects of the invention,an ultrasonic device, an ultrasonic probe, an ultrasonic diagnosticdevice, and the like that can drive a signal in response to a distanceto an object can be provided.

Means Used to Solve the Above-Mentioned Problems

According to one aspect of the invention, an ultrasonic device includesa substrate, a plurality of first ultrasonic elements having a resonancecharacteristic of a first frequency disposed on the substrate, and aplurality of second ultrasonic elements having a resonancecharacteristic of a second frequency, which is lower than the firstfrequency, disposed on the substrate. The plurality of first ultrasonicelements are arranged along a first direction to make a firsthigh-frequency ultrasonic element line to an n-th high-frequencyultrasonic element line (n is an integer of more than 2). The pluralityof second ultrasonic elements are arranged along the first direction tomake a first low-frequency ultrasonic element line to an n-thlow-frequency ultrasonic element line. The first high-frequencyultrasonic element line to the n-th high-frequency ultrasonic elementline are arranged along a second direction which intersects with thefirst direction. The first low-frequency ultrasonic element line to then-th low-frequency ultrasonic element line are arranged along the seconddirection. Each of the first ultrasonic elements and each of the secondultrasonic elements have an opening provided in the substrate, avibrating membrane that covers the opening, and a piezo element partprovided on the vibrating membrane. A length in the second direction ofthe opening of each of the first ultrasonic elements is shorter than alength in the second direction of the opening of each of the secondultrasonic elements.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the attached drawings which form a part of thisoriginal disclosure:

FIG. 1A and FIG. 1B show basic configuration examples of ultrasonicelements;

FIG. 2A and FIG. 2B show a maximum amplitude of ultrasonic wavesoutputted in a case that a square wave and a sine wave are inputted toan ultrasonic element of resonance frequency 1.5 MHz;

FIG. 3A and FIG. 3B show a maximum amplitude of ultrasonic wavesoutputted in a case that a square wave and a sine wave are inputted toan ultrasonic element of resonance frequency 5.5 MHz;

FIG. 4A and FIG. 4B show an ultrasonic signal waveform in a case that asquare wave of frequencies 2.5 MHz and 5.5 MHz is inputted to anultrasonic element of resonance frequency 5.5 MHz;

FIG. 5A and FIG. 5B show an absolute value of an ultrasonic signal andan envelope demodulation signal waveform in a case that a square waveand a sine wave of frequency 5.5 MHz are inputted to an ultrasonicelement of resonance frequency 5.5 MHz;

FIG. 6A and FIG. 6B show an absolute value of an ultrasonic signal andan envelope demodulation signal waveform in a case that a square waveand a sine wave of frequency 2.5 MHz are inputted to an ultrasonicelement of resonance frequency 5.5 MHz;

FIG. 7 shows a configuration example of an ultrasonic device;

FIG. 8 shows a configuration example of a processing device;

FIG. 9A, FIG. 9B, and FIG. 9C show configuration examples of switchcircuits;

FIG. 10 shows a basic configuration example of an ultrasonic probe andan ultrasonic diagnostic device;

FIG. 11 is the first flowchart showing a flow of driving and imagegeneration in an ultrasonic diagnostic device;

FIG. 12 is the second flowchart showing a flow of driving and imagegeneration in an ultrasonic diagnostic device; and

FIG. 13A and FIG. 13B are concrete configuration examples of ultrasonicdiagnostic devices. FIG. 13C is a concrete configuration example of anultrasonic probe.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, the preferred embodiments of the invention will beexplained in detail. By the way, the embodiments explained below shallnot be construed as unreasonably limiting the subject matter of theinvention described in the claims, and all the elements explained in theembodiments are not necessarily essential to the solving means of theinvention.

1. Ultrasonic Element

FIG. 1A and FIG. 1B show a basic configuration example of an ultrasonicelement UE including an ultrasonic device of the present embodiment. Theultrasonic element UE of the present embodiment has a vibrating membrane(membrane, supporting member) MB, and a piezo element part. The piezoelement part has a lower electrode (first electrode layer) EL1, apiezoelectric body film (piezoelectric body layer) PE, and an upperelectrode (second electrode layer) EL2. By the way, the ultrasonicelement UE of the present embodiment is not limited to the configurationof FIG. 1 so that various modifications omitting a part of theconfiguration elements, replacing to other configuration elements,adding other configuration elements, and the like can be possible.

FIG. 1A is a plan view of the ultrasonic element UE formed on asubstrate (silicon substrate) SUB. The plan view is a view from adirection perpendicular to the substrate in the element forming surfaceside. FIG. 1B is a cross-section view showing a cross-section along A-A′of FIG. 1A.

The first electrode layer EL1 is formed on an upper layer of thevibrating membrane MB by, for example, a metal thin film. This firstelectrode layer EL1 extends to outside of the element forming area asshown in FIG. 1A and it can be a wire connecting to an adjacentultrasonic element UE.

The piezoelectric body film PE is formed by for example, a PZT(zirconate titanate) thin film, and it is provided to cover at least apart of the first electrode element EL1. By the way, the material of thepiezoelectric body film PE is not limited to PZT, and for example, leadtitanate (PbTiO₃), lead zirconate (PbZrO₃), lead titanate lantern ((Pb,La) TiO₃), and the like can be used.

The second electrode layer EL2 is formed by for example, a metal thinfilm, and it is provided to cover at least a part of the piezoelectricbody film PE. The second electrode layer EL2 extends to outside of theelement forming area as shown in FIG. 1A, and it can be a wireconnecting to an adjacent ultrasonic element UE.

The vibrating membrane (membrane) MB configured by, for example, twolayers of SiO₂ thin film and ZrO₂ thin film is provided to cover anopening OP. The vibrating membrane MB supports the piezoelectric bodyfilm PE and the first and second electrode layers EL1, EL2, and also, itvibrates in accordance with expansion and contraction of thepiezoelectric body film PE so that it can generate ultrasonic wave.

A cavity area CAV is formed by etching such as the reactive ion etching(RIE), or the like from the back surface (surface on which the elementis not formed) side of the silicon substrate SUB. An ultrasonic wave isoutputted from the opening OP of the cavity area CAV.

The lower electrode of the ultrasonic element UE is formed by the firstelectrode layer EL1, and the upper electrode is formed by the secondelectrode layer EL2. Concretely, a part of the first electrode layer EL1covered by the piezoelectric body film PE forms the lower electrode, anda part of the second electrode layer EL2 covered by the piezoelectricbody film PE forms the upper electrode. That is, the piezoelectric bodyfilm PE is provided between the lower electrode and the upper electrode.

The voltage is impressed between the lower electrode and the upperelectrode, that is, between the first electrode layer EL1 and the secondelectrode layer EL2 so that the piezoelectric film PE expands andcontracts in-plane direction. One surface of the piezoelectric body filmPE connects to the vibrating membrane MB through the first electrodelayer EL1. The second electrode layer EL2 is formed on the other surfaceof the piezoelectric body film PE, but another layer is not formed onthe second electrode layer EL2. Because of this, the vibrating membraneMB side of the piezoelectric film PE is difficult to perform expansionand contraction, and the second electrode layer EL2 side of thepiezoelectric film PE becomes easy to perform expansion and contraction.Accordingly, when the voltage is impressed to the piezoelectric bodyfilm PE, the deflection occurs as convex on the cavity area CAV side sothat the vibrating membrane MB deflects. The vibrating membrane MBvibrates in a film thickness direction by impressing AC voltage to thepiezoelectric body film PE so that the ultrasonic wave is outputted fromthe opening OP by the vibration of the vibrating membrane MB. Thevoltage impressing to the piezoelectric body film PE is, for example, 10to 30V, and the frequency is, for example, 1 to 10 MHz.

The ultrasonic element UE has a resonance characteristic determined bythe length LOP of the short side of the opening OP. As the length of theshort side of the opening is longer, the frequency of resonance becomeslower, and as the length of the short side of the opening is shorter,the frequency of resonance becomes higher. The length LOP of the shortside of the opening OP providing an ultrasonic element UE that has aresonance characteristic of the first frequency is shorter than thelength LOP of the short side of the opening OP providing an ultrasonicelement UE that has a resonance characteristic of the second frequencywhich is lower than the first frequency.

The phrase “the ultrasonic element UE has a resonance characteristic ofthe first frequency” means that the ultrasonic wave outputted from theultrasonic element UE has a peak in the first frequency.

As described later, in the ultrasonic device 100 of the presentembodiment, by providing two types of ultrasonic elements havingdifferent length LOP of the short side of the opening OP, an ultrasonicelement having high resonance frequency and an ultrasonic element havinglow resonance frequency can be mixedly arranged on one substrate.

As a signal (driving signal) that is impressed to the piezoelectric bodyfilm PE of the ultrasonic element UE, for example, a square wave, a sinewave, or the like can be used. FIG. 2A and FIG. 2B show a maximumamplitude of ultrasonic waves outputted in a case that a square wave anda sine wave are inputted to an ultrasonic element of resonance frequency1.5 MHz. The horizontal axis is the frequency of the inputted squarewave or the inputted sine wave.

As shown in FIG. 2A, in a case of the square wave input, the maximumamplitude becomes a peak at resonance frequency 1.5 MHz and itsvicinity. In addition, the maximum amplitude becomes larger at the lowerfrequency region (lower than 1.8 MHz). On the other hand, as shown inFIG. 2B, in a case of the sine wave input, the maximum amplitude becomesa peak at resonance frequency 1.5 MHz and its vicinity and the maximumamplitude is reduced at the lower frequency region. Also, when themaximum amplitudes at the vicinity of resonance frequency 1.5 MHz arecompared, the case that the square wave is inputted is larger than thecase that the sine wave is inputted.

FIG. 3A and FIG. 3B show a maximum amplitude of ultrasonic wavesoutputted in a case that a square wave and a sine wave are inputted toan ultrasonic element of resonance frequency 5.5 MHz. As shown in FIG.3A, in a case of the square wave input, the maximum amplitude becomes apeak at resonance frequency 5.5 MHz and its vicinity. In addition, themaximum amplitude becomes larger at the lower frequency region (lowerthan 2.6 MHz). On the other hand, as shown in FIG. 3B, in a case of thesine wave input, the maximum amplitude becomes high at resonancefrequency 5.5 MHz and its vicinity and the maximum amplitude is reducedat the lower frequency region. Also, when the maximum amplitudes at thevicinity of resonance frequency 5.5 MHz are compared, there are nosignificant differences between the case that the square wave isinputted and the case that the sine wave is inputted.

In this manner, in a case that the ultrasonic element of lower resonancefrequency (e.g., 1.5 MHz) is driven, it is better to input the squarewave so that a high ultrasonic intensity can be obtained. In a case thata distance between the ultrasonic element and an object is far, the highultrasonic intensity is required to obtain the desired resolutionbecause the intensity is attenuated when an ultrasonic wave outputtedfrom the ultrasonic element reaches to the object and the reflected waveis returned to the ultrasonic element. Also, the ultrasonic wave of thelower frequency is smaller attenuation than the ultrasonic wave of thehigher frequency in a medium. From the above description, in a case thatthe distance between the ultrasonic element and the object is far, toobtain the desired resolution, it has an advantage that the ultrasonicelement that the resonance frequency is low is driven by the squarewave.

FIG. 4A and FIG. 4B show an ultrasonic signal waveform in a case that asquare wave of frequencies 2.5 MHz and 5.5 MHz is inputted to anultrasonic element of resonance frequency 5.5 MHz. The broken lineindicates a square wave signal and the continuous line indicates anultrasonic wave signal.

In FIG. 4A, a time (pulse width) from the rise of the input signal tothe fall of the input signal corresponds to approximately 2 cycles ofthe vibration of the vibrating membrane. Thus, even though it is thesquare wave of 2.5 MHz, the ultrasonic element of resonance frequency5.5 MHz can be driven. This is the reason that the maximum amplitudes ofthe ultrasonic waves in the frequency region lower than the resonancefrequency become large as shown in FIG. 2A and FIG. 3A. On the otherhand, in FIG. 4B, the pulse width of the input signal corresponds to 1cycle of the vibration of the vibrating membrane so that the ultrasonicwave of resonance frequency 5.5 MHz is outputted.

FIG. 5A and FIG. 5B show an absolute value of an ultrasonic signal andan envelope demodulation signal waveform in a case that a square waveand a sine wave of frequency 5.5 MHz are inputted to an ultrasonicelement of resonance frequency 5.5 MHz. In each drawing, the continuousline indicates an absolute value of an ultrasonic signal and the brokenline indicates an envelope demodulation signal. In addition, eachdrawing shows a time width (half bandwidth) as to become a half value (avalue of ½) of a maximum value (peak value) of an envelope demodulationsignal.

As shown in FIG. 5A and FIG. 5B, the half bandwidth is 0.315 μs in acase of the square wave input. On the other hand, the half bandwidth is0.26 μs in a case of the sine wave input. The half bandwidth is shorter,and this means that the time from the rise of the intensity of theultrasonic signal to the fall of the intensity of the ultrasonic signalis short.

FIG. 6A and FIG. 6B show an absolute value of an ultrasonic signal andan envelope demodulation signal waveform in a case that a square waveand a sine wave of frequency 2.5 MHz are inputted to an ultrasonicelement of resonance frequency 5.5 MHz.

As shown in FIG. 6A and FIG. 6B, an absolute value of an ultrasonicsignal in a case of the square wave input is larger than an absolutevalue of an ultrasonic signal in a case of the sine wave input, and thatis, the intensity of the ultrasonic wave is high. As described in FIG.4A, it is because the time (pulse width) from the rise of the squarewave signal to the fall of the square wave signal corresponds to 2cycles of the vibration of the vibrating membrane. Also, in the samemanner as FIG. 5A and FIG. 5B, the half bandwidth is 0.43 μs in a caseof the square wave input. On the other hand, the half bandwidth is 0.32μs in a case of the sine wave input so that it becomes smaller.

Because of this, in a case of the square wave input, the time from therise of the intensity of the ultrasonic signal to the fall of theintensity of the ultrasonic signal becomes longer, and in a case of thesine wave input, the time from the rise of the intensity of theultrasonic signal to the fall of the intensity of the ultrasonic signalbecomes shorter. In a case that a distance between the ultrasonicelement and an object is close, the intensity of the ultrasonic wave canbe low because the attenuation of the intensity is small when anultrasonic wave outputted from the ultrasonic element reaches to theobject and the reflected wave is returned to the ultrasonic element. Onthe other hand, the time from the timing that the ultrasonic wave istransmitted to the timing that the reflected wave (echo) is receivedbecomes shorter because the distance is close. When the time from therise of the intensity of the transmitted ultrasonic wave signal to thefall of the intensity of the transmitted ultrasonic wave signal becomeslonger, it is difficult to obtain the desired resolution because thereceived echo signal and the transmitted ultrasonic wave signal areoverlapped. Accordingly, in a case that a distance between theultrasonic element and an object is close, to obtain the desiredresolution, it has an advantage that the ultrasonic element that theresonance frequency is high is driven by the sine wave.

As described above, to obtain the desired resolution, in a case that adistance between the ultrasonic element and an object is far, it has anadvantage that the ultrasonic element that the resonance frequency islow is driven by the square wave, and on the other hand, in a case thata distance between the ultrasonic element and an object is close, it hasan advantage that the ultrasonic element that the resonance frequency ishigh is driven by the sine wave.

2. Ultrasonic Device

FIG. 7 shows a configuration example of an ultrasonic device. Theultrasonic device of the present configuration example includes thefirst to n-th (n is integer number of more than 2) high-frequencyultrasonic element lines H_UEC1 to H_UECn, the first to n-th (n isinteger number of more than 2) low-frequency ultrasonic element linesL_UEC1 to L_UECn, the first to n-th high-frequency drive electrode wiresH_DL1 to H_DLn, the first to n-th low-frequency drive electrode wiresL_DL1 to L_DLn, and the first to m-th (m is integer number of more than2) common electrode wires CL1 to CLm (in the broad sense, a plurality ofcommon electrode wires). In a case of FIG. 7, it indicates, for example,m=8, n=6, but it can be other values. By the way, the ultrasonic device100 of the present embodiment is not limited to the configuration ofFIG. 7, and various modifications such as omitting a part of theconfiguration elements, replacing to other configuration elements,adding other configuration elements, and the like are possible.

The first to n-th high-frequency ultrasonic element lines H_UEC1 toH_UECn include a plurality of ultrasonic elements H_UE having aresonance characteristic of the first frequency that are arranged alongthe first direction D1. The first to n-th high-frequency ultrasonicelement lines H_UEC1 to H_UECn are arranged along the second direction,which intersects with the first direction D1. The ultrasonic elementsH_UE having a resonance characteristic of the first frequency are theultrasonic element as shown in FIG. 1A and FIG. 1B, and the length LOPof the short side of its opening OP is shorter than the length LOP ofthe short side of the opening OP of the ultrasonic elements L_UE havinga resonance characteristic of the second frequency.

The first frequency is, for example, 5.5 MHz, and the second frequencyis, for example, 1.5 MHz, but it can be other than those frequencies.Also, the length LOP of the short side of the opening OP of theultrasonic elements H_UE having a resonance characteristic of the firstfrequency is, for example, 25 μm, and the length LOP of the short sideof the opening OP of the ultrasonic elements L-UE having a resonancecharacteristic of the second frequency is, for example, 50 μm, but itcan be other than those lengths.

The first to n-th low-frequency ultrasonic element lines L_UEC1 toL_UECn include a plurality of ultrasonic elements L_UE having aresonance characteristic of the second frequency, which is lower thanthe first frequency, that are arranged along the first direction D1.And, the first to n-th low-frequency ultrasonic element lines L_UEC1 toL_UECn are arranged along the second direction D2. The ultrasonicelements L_UE having a resonance characteristic of the second frequencyare the ultrasonic element as shown in FIG. 1A and FIG. 1B, and thelength LOP of the short side of its opening OP is longer than the lengthLOP of the short side of the opening OP of the ultrasonic elements H_UEhaving a resonance characteristic of the first frequency.

The first to n-th high-frequency ultrasonic element lines H_UEC1 toH_UECn and the first to n-th low-frequency ultrasonic element linesL_UEC1 to L_UECn are alternately arranged along the second direction D2.For example, as shown in FIG. 7, it is arranged in order of H_UEC1,L_UEC1, H_UEC2, L_UEC2, . . . , H_UEC6, L_UEC6. However, it is notnecessary to alternate the high-frequency ultrasonic element line andthe low-frequency ultrasonic element line.

The first to n-th high-frequency drive electrode wires H_DL1 to H_DLnare wired along the first direction D1. And, the i-th (i is the integernumber of 1≦i≦n) high-frequency drive electrode wire H_DLi is connectedto the first electrode that is provided in each of the plurality ofultrasonic elements H_UE that configure the i-th high-frequencyultrasonic element line H_UECi.

The first to n-th low-frequency drive electrode wires L_DL1 to L_DLn arewired along the first direction D1. And, the j-th (j is the integernumber of 1≦j≦n) low-frequency drive electrode wire L_DLj is connectedto the first electrode that is provided in each of the plurality ofultrasonic elements L_UE that configure the i-th low-frequencyultrasonic element line L_UECj.

During a transmission period to output an ultrasonic wave, the first ton-th drive signals VDR1 to VDRn outputted from a processing device 200,which will be described later, are supplied to each ultrasonic elementthrough the high-frequency drive electrode wires H_DL1 to H_DLn and thelow-frequency drive electrode wires L_DL1 to L_DLn. Also, during areceiving period to receive an ultrasonic echo signal, a receivingsignal from each ultrasonic element is outputted through thehigh-frequency drive electrode wires H_DL1 to H_DLn and thelow-frequency drive electrode wires L_DL1 to L_DLn.

The first to m-th common electrode wires CL1 to CLm (in a broad sense, aplurality of common electrode wires) are wired along the seconddirection D2. The second electrode provided in each of the plurality ofultrasonic elements HUE that configure the i-th high-frequencyultrasonic element line H_UECi is connected to any one of the first tom-th common electrode wires CL1 to CLm. Also, the second electrodeprovided in each of the plurality of ultrasonic elements L_UE thatconfigure the j-th low-frequency ultrasonic element line L_UECj isconnected to any one of the first to m-th common electrode wires CL1 toCLm.

The first to m-th common electrode wires CL1 to CLm are commonlyconnected to a common voltage line CML, and the common voltage VCOM issupplied to the common voltage line CML. The common voltage VCOM can bea certain amount of DC voltage, and it does not have to be OV, that is,ground electric potential (ground potential).

3. Processing Device

FIG. 8 shows a configuration example of a processing device 200 of thepresent embodiment. The processing device 200 of the present embodimentis a processing device to perform processes of transmitting andreceiving an ultrasonic wave to the ultrasonic device 100. This includesa transmitter 210, a controller 220, a switch part 230, and a receiver240. By the way, the processing device 200 of the present embodiment isnot limited to the configuration of FIG. 8, and various modificationssuch as omitting a part of the configuration elements, replacing toother configuration elements, adding other configuration elements, andthe like are possible.

The transmitter 210 outputs the first to n-th driving signals VDR1 toVDRn (in the broad sense, driving signals) to the first to n-thhigh-frequency drive electrode wires H_DL1 to H_DLn of the ultrasonicdevice 100 and the first to n-th low-frequency drive electrode wiresL_DL1 to L_DLn (in the broad sense, drive electrode wires) of theultrasonic device 100 through the switch 230.

Concretely, the transmitter 210 outputs sine wave driving signals VDR1to VDRn to the high-frequency ultrasonic element lines H_UEC1 to H_UECnin the first mode. In the second mode, the transmitter 210 outputssquare wave driving signals VDR1 to VDRn to the low-frequency ultrasonicelement lines L_UEC1 to L_UECn. Also, in the third mode, the transmitter210 outputs the square wave driving signals VDR1 to VDRn to both of thehigh-frequency ultrasonic element lines H_UEC1 to H_UECn and thelow-frequency ultrasonic element lines L_UEC1 to L_UECn. The transmitter210 can be configured by, for example, a pulse generator, anamplification equipment, and the like.

In the first mode, the sine wave driving signals VDR1 to VDRn can beoutputted to the high-frequency ultrasonic element lines H_UEC1 toH_UECn so that as described above, in a case that a distance between theultrasonic element and an object is close, the high resolution can beobtained. In the second mode, the square wave driving signals VDR1 toVDRn can be outputted to the low-frequency ultrasonic element linesL_UEC1 to L_UECn so that in a case that a distance between theultrasonic element and an object is far, the high resolution can beobtained. Also, in the third mode, the square wave driving signals VDR1to VDRn can be outputted to both of the high-frequency ultrasonicelement lines H_UEC1 to H_UECn and the low-frequency ultrasonic elementlines L_UEC1 to L_UECn so that this can be used in a case that adistance between the ultrasonic element and an object is unclear, or ina case that it desires to detect both a close object and a far object.

The receiver 240 performs a receiving process of the receiving signalsVR1 to VRn from the ultrasonic device 100 through the switch part 230.Concretely, it performs amplifying the receiving signals, gain setting,frequency setting, A/D conversion (Analog/Digital conversion), and thelike, and it is outputted to an image generating part 320 as detecteddata (detected information) (FIG. 10). The receiver 240 can beconfigured by a low noise amplifier, a voltage-controlled attenuator, aprogrammable gain amplifier, a low-pass filter, an A/D converter, andthe like.

The controller 220 controls the transmitter 210, the receiver 240, andthe switch 230. Concretely, the controller 220 controls the generatingand outputting processes of the driving signals VDR1 to VDRn to thetransmitter 210, and the receiving process of the receiving signals VR1to VRn to the receiver 240, and the controller 220 controls the switchpart 230 to switch transmitter and receiver and to switch thehigh-frequency ultrasonic element line H_UECi and the low-frequencyultrasonic element line L_UECi. The controller 220 can be realized by,for example, FPGA (Field-Programmable Gate Array).

The switch part 230 selects at least one of the high-frequencyultrasonic element lines H_UEC1 to H_UECn and the low-frequencyultrasonic element lines L_UEC1 to L_UECn based on the control of thecontroller 220, and the driving signals VDR1 to VDRn are outputted to aselected ultrasonic element line from the transmitter 210.

Concretely, the switch part 230 selects the high-frequency ultrasonicelement lines H_UEC1 to H_UECn in the first mode. And, during thetransmitting period in the first mode, the driving signals VDR1 to VDRnare outputted to the high-frequency ultrasonic element lines H_UEC1 toH_UECn from the transmitter 210. Also, during the receiving period inthe first mode, the receiving signals VR1 to VRn are received from thehigh-frequency ultrasonic element lines H_UEC1 to H_UECn, and it isoutputted to the receiver 240.

The switch part 230 selects the low-frequency ultrasonic element linesL_UEC1 to L_UECn in the second mode. And, during the transmitting periodin the second mode, the driving signals VDR1 to VDRn are outputted tothe low-frequency ultrasonic element lines L_UEC1 to L_UECn from thetransmitter 210. Also, during the receiving period in the second mode,the receiving signals VR1 to VRn are received from the low-frequencyultrasonic element lines L_UEC1 to L_UECn, and it is outputted to thereceiver 240.

The switch part 230 selects both of the high-frequency ultrasonicelement lines H_UEC1 to H_UECn and the low-frequency ultrasonic elementlines L_UEC1 to L_UECn in the third mode. And, during the transmittingperiod in the third mode, the driving signals VDR1 to VDRn are outputtedto both of the high-frequency ultrasonic element lines H_UEC1 to H_UECnand the low-frequency ultrasonic element lines L_UEC1 to L_UECn from thetransmitter 210. Also, during the receiving period in the third mode,the receiving signals VR1 to VRn are received from both of thehigh-frequency ultrasonic element lines H_UEC1 to H_UECn and thelow-frequency ultrasonic element lines L_UEC1 to L_UECn, and it isoutputted to the receiver 240.

More specifically, the switch part 230 includes switch circuits SW1 toSWn. For example, in the first mode, the SW1 selects the firsthigh-frequency ultrasonic element line H_UEC1. In the second mode, itselects the first low-frequency ultrasonic element line L_UEC1. In thethird mode, it selects both of the first high-frequency ultrasonicelement line H_UEC1 and the first low-frequency ultrasonic element lineL_UEC1.

FIG. 9A, FIG. 9B, and FIG. 9C show configuration examples of switchcircuits. The switch circuit SW1 includes switch elements SW1 a, SW1 b,SW1 c. By the way, the switch circuit SW1 of the present embodiment isnot limited to the configuration of FIGS. 9A-9C, and variousmodifications such as omitting a part of the configuration elements,replacing to other configuration elements, adding other configurationelements, and the like are possible.

FIG. 9A shows a case of the first mode. In the first mode, the SW1 a isset in on-state and the SW1 b is set in off-state so that thehigh-frequency ultrasonic element line H_UEC1 is selected. And, duringthe transmitting period, the SW1 c is set in a state as indicated by thecontinuous line, and the driving signal VDR1 is outputted to thehigh-frequency ultrasonic element line H_UEC1 from the transmitter 210.Also, during the receiving period, the SW1 c is set in a state asindicated by the broken line, and the receiving signal VR1 is outputtedto the receiver 240 from the high-frequency ultrasonic element lineH_UEC1.

FIG. 9B shows a case of the second mode. In the second mode, the SW1 ais set in off-state and the SW1 b is set in on-state so that thelow-frequency ultrasonic element line L_UEC1 is selected. And, duringthe transmitting period, the SW1 c is set in a state as indicated by thecontinuous line, and the driving signal VDR1 is outputted to thelow-frequency ultrasonic element line L_UEC1 from the transmitter 210.Also, during the receiving period, the SW1 c is set in a state asindicated by the broken line, and the receiving signal VR1 is outputtedto the receiver 240 from the low frequency ultrasonic element lineL_UEC1.

FIG. 9C shows a case of the third mode. In the third mode, both of theSW1 a and the SWb1 are set in on-state so that both of thehigh-frequency ultrasonic element line H_UEC1 and the low-frequencyultrasonic element line L_UEC1 are selected. And, during thetransmitting period, the SW1 c is set in a state as indicated by thecontinuous line, and the driving signal VDR1 is outputted to both of thehigh-frequency ultrasonic element line H_UEC1 and the low-frequencyultrasonic element line L_UEC1 from the transmitter 210. Also, duringthe receiving period, the SW1 c is set in a state as indicated by thebroken line, and the receiving signal VR1 is outputted to the receiver240 from both of the high-frequency ultrasonic element line H_UEC1 andthe low-frequency ultrasonic element line L_UEC1.

By the way, regarding other switch circuits SW2 to SWn, it can be thesame configurations as FIG. 9A, FIG. 9B, and FIG. 9C.

As described above, according to the ultrasonic device 100 and theprocessing device 200 of the present embodiment, in the first mode, asine wave driving signal can be outputted to the high-frequencyultrasonic element lines. In the second mode, a square wave drivingsignal can be outputted to the low-frequency ultrasonic element lines.In this way, the first mode is used for an object which is close to theultrasonic device 100, and the second mode is used for an object whichis far from the ultrasonic device 100 so that the desired resolution canbe obtained for either case. Also, in the third mode, a square wavedriving signal can be outputted to both of the high-frequency ultrasonicelement lines and the low-frequency ultrasonic element lines. In thisway, the desired resolution can be obtained in a case that a distancebetween the ultrasonic element and an object is unclear, or in a casethat it desires to detect both of an object in close distance and anobject in far distance, or the like.

4. Ultrasonic Probe and Ultrasonic Diagnostic Device

FIG. 10 shows a basic configuration example of an ultrasonic probe 300and an ultrasonic diagnostic device 400. The ultrasonic probe 300includes the ultrasonic device 100 and the processing device 200. Theultrasonic diagnostic device 400 includes the ultrasonic probe 300, amain controller 310, an image generating part 320, a User Interface (UI)part 330, and a display part 340. By the way, it can be a configurationthat the ultrasonic device 100 can be released or can be replaced fromthe ultrasonic probe 300.

The main controller 310 controls the ultrasonic probe 300 to perform theultrasonic wave transmitting and receiving control, and it controls theimage generating part 320 to perform an image processing of the detecteddata, and the like. By the way, a part of the control performed by themain controller 310 can be performed by the controller 220 of theprocessing device 200, and a part of the control performed by thecontroller 220 can be performed by the main controller 310 of theultrasonic diagnostic device 400.

The image generating part 320 receives detection data from the receivingpart 240, performs the necessary image processing, and generates imagedata for a display. Specifically, the image generating part 320generates the first image data based on a receiving signal from thehigh-frequency ultrasonic element lines H_UEC1 to H_UECn in the firstmode, and the image generating part 320 generates the second image databased on a receiving signal from the low-frequency ultrasonic elementlines L_UEC1 to L_UECn in the second mode. Also, in the third mode, thethird image data is generated based on a receiving signal from thehigh-frequency ultrasonic element lines H_UEC1 to H_UECn and thelow-frequency ultrasonic element lines L_UEC1 to L_UECn. In addition, itperforms an image processing to synthesize the first image data and thesecond image data.

The first image data contains an image that a desired resolution can beobtained for an object located in a range of the first distance. Thesecond image data contains an image that a desired resolution can beobtained for an object located in a range of the second distance that isfarther than the range of the first distance. Also, the third image datacontains an image that a desired resolution can be obtained for anobject located in the ranges of both of the first and second distances,and for an object located in a middle of the ranges of the first andsecond distances. For example, the range of the first distance is 1 to 5cm, and the range of the second distance is 10 to 15 cm.

In this way, by generating the first image data in the first mode for anobject in a close distance, and by generating the second image data inthe second mode for an object in a far distance, the desired resolutioncan be obtained for either case. Also, in a case that a distance to anobject is unclear, or in a case that a detection for an object in a widerange of distance between a close distance to a far distance is desired,by generating the third image data in the third mode, the desiredresolution can be obtained. In addition, by performing an imageprocessing to synthesize the first image data and the second image data,an object in a close distance and an object in a far distance can beefficiently displayed in one screen.

The User Interface (UI) part 330 outputs a necessary command (command)to the main control part 310 based on the user's control (e.g., touchpanel control, or the like). The display part 340 is, for example, aliquid crystal display, and the like, and it displays image data fordisplay generated from the image generating part 320.

FIG. 11 is the first flowchart showing a flow of driving and imagegeneration in an ultrasonic diagnostic device 400 of the presentembodiment. The flow shown in FIG. 11 is executed by the controller 220and the main controller 310.

First, the first mode is executed (Step S1). That is, the switch part230 selects the high-frequency ultrasonic element lines, and thetransmitter 210 drives the high-frequency ultrasonic element lines by asine wave through the switch part 230. And, the receiver 240 receives areceiving signal from the high-frequency ultrasonic element linesthrough the switch part 230 so as to perform the receiving process.

Next, the image generating part 320 receives detection data from thereceiving part 240 and generates the first image data (Step S2). Themain control part 310 determines whether or not the resolution satisfiesthe specification for the first image data (Step S3). The evaluation ofthe resolution can be performed by, for example, a contrast detectionused for an autofocus in a digital camera, or the like. That is, thecontrast is detected from the image data, and when the detected contrastis more than the predetermined value, it determines that the resolutionsatisfies the specification. When the detected contrast is less than thepredetermined value, it determines that the resolution does not satisfythe specification. When the resolution satisfies the specification, thedisplay part 340 displays the first image data (Step S4).

On the other hand, in a case that the resolution does not satisfy thespecification, the second mode is executed (Step S5). That is, theswitch part 230 selects the low-frequency ultrasonic element lines, andthe transmitter 210 drives the low-frequency ultrasonic element lines bya square wave through the switch part 230. And, the receiver 240receives a receiving signal from the low-frequency ultrasonic elementlines through the switch part 230 so as to perform the receivingprocess.

Next, the image generating part 320 receives the detection data from thereceiving part 240 and generates the second image data (Step S6). Themain controller 310 determines whether or not the resolution satisfiesthe specification for the second image data (Step S7). When theresolution satisfies the specification, the display part 340 displaysthe second image data (Step S8).

On the other hand, when the resolution does not satisfy thespecification, the third mode is executed (Step S9). That is, the switchpart 230 selects both of the high-frequency ultrasonic element lines andthe low-frequency ultrasonic element lines, and the transmitter 210drives both of the high-frequency ultrasonic element lines and thelow-frequency ultrasonic element lines by a square wave through theswitch part 230. And, the receiver 240 receives a receiving signal fromboth of the high-frequency ultrasonic element lines and thelow-frequency ultrasonic element lines through the switch part 230 so asto perform the receiving process.

Next, the image generating part 320 receives the detection data from thereceiving part 240 and generates the third image data (Step S10), andthe display part 340 displays the third image data (Step S11).

As described, according to the ultrasonic diagnostic device 400 of thepresent embodiment, the first, the second, and the third modes areautomatically switched in response to a distance to an object to bedetected and it can perform probing. In this way, regardless a distanceto an object to be detected, a clear echo image can be obtained so thatan accurate diagnosis becomes possible.

FIG. 12 is the second flowchart showing a flow of driving and imagegeneration in an ultrasonic diagnostic device 400 of the presentembodiment. The flow shown in FIG. 12 is executed by the controller 220and the main controller 310 in the same manner as the flow of FIG. 11.

First, the first mode is executed (Step S21). That is, the switch part230 selects the high-frequency ultrasonic element lines, and thetransmitter 210 drives the high-frequency ultrasonic element lines by asine wave through the switch part 230. And, the receiver 240 receives areceiving signal from the high-frequency ultrasonic element linesthrough the switch part 230 so as to perform the receiving process.

And, the image generating part 320 receives the detection data from thereceiver 240 and generates the first image data (Step S22).

Next, the second mode is executed (Step S23). That is, the switch part230 selects the low-frequency ultrasonic element lines, and thetransmitter 210 drives the low-frequency ultrasonic element lines by asquare wave through the switch part 230. And, the receiver 240 receivesa receiving signal from the low-frequency ultrasonic element linesthrough the switch part 230 so as to perform the receiving process.

And, the image generating part 320 receives the detection data from thereceiver 240 and generates the second image data (Step S24).

Next, the image generating part 320 synthesizes the first image data andthe second image data (Step S25), and the display part 340 displays thesynthesized image data (Step S26).

As described, according to the ultrasonic diagnostic device 400 of thepresent embodiment, by synthesizing an image in the first mode and animage in the second mode, an object in a close distance and an object ina far distance can be efficiently displayed in one screen.

FIG. 13A and FIG. 13B show the concrete configuration examples of theultrasonic diagnostic devices 400 of the present embodiment. FIG. 13Ashows a portable type ultrasonic diagnostic device 400, and FIG. 13Bshows a floor-standing type ultrasonic diagnostic device 400.

Both the portable type and the floor-standing type ultrasonic diagnosticdevices 400 include the ultrasonic probe 300, a cable CB, and anultrasonic diagnostic device main body 410. The ultrasonic probe 300 isconnected to the ultrasonic diagnostic device main body 410 by the cableCB. The ultrasonic diagnostic device main body 410 includes the displaypart 340 that displays an image data for display.

FIG. 13C is a concrete configuration example of the ultrasonic probe 300of the present embodiment. The ultrasonic probe 300 includes the probehead 301 and the probe main body 302. As shown in FIG. 13C, the probehead 301 is releasable from the probe main body 302.

The probe head 301 includes the ultrasonic device 100, a supportingmember SUP, a connecting member 130 that connects with a device undertest, a protective member (protective film) that protects the ultrasonicdevice 100, and a connector CNa, and a probe case 140. The ultrasonicdevice 100 is provided between the connecting member 130 and thesupporting member SUP.

The probe main body 302 includes the processing device 200 and the probemain body side connector CNb. The probe main body side connector CNbconnects with the probe head side connector CNa. The probe main body 302is connected to the ultrasonic diagnostic device main body by the cableCB.

While the present embodiment has been explained in detail as above, itwill be apparent to those skilled in the art that various changes andmodifications can be made herein without substantially departing fromthe subject matter and the effect of the invention. Therefore, suchchanges and modifications are included in the scope of the invention.For example, the terms used in the specification or the drawings atleast once together with a different term having a broader or similarmeaning can be replaced with the different term in any portion of thespecification or the drawings. Also, the configurations and theoperations of the processing device, the ultrasonic device, theultrasonic probe, and the ultrasonic diagnostic device are not limitedto the described present embodiment, and various changes andmodifications are possible.

GENERAL INTERPRETATION OF TERMS

In understanding the scope of the present invention, the term“comprising” and its derivatives, as used herein, are intended to beopen ended terms that specify the presence of the stated features,elements, components, groups, integers, and/or steps, but do not excludethe presence of other unstated features, elements, components, groups,integers and/or steps. The foregoing also applies to words havingsimilar meanings such as the terms, “including”, “having” and theirderivatives. Also, the terms “part,” “section,” “portion,” “member” or“element” when used in the singular can have the dual meaning of asingle part or a plurality of parts. Finally, terms of degree such as“substantially”, “about” and “approximately” as used herein mean areasonable amount of deviation of the modified term such that the endresult is not significantly changed. For example, these terms can beconstrued as including a deviation of at least ±5% of the modified termif this deviation would not negate the meaning of the word it modifies.

While only selected embodiments have been chosen to illustrate thepresent invention, it will be apparent to those skilled in the art fromthis disclosure that various changes and modifications can be madeherein without departing from the scope of the invention as defined inthe appended claims. Furthermore, the foregoing descriptions of theembodiments according to the present invention are provided forillustration only, and not for the purpose of limiting the invention asdefined by the appended claims and their equivalents.

What is claimed is:
 1. An ultrasonic device comprising: a substrate; aplurality of first ultrasonic elements having a resonance characteristicof a first frequency disposed on the substrate; and a plurality ofsecond ultrasonic elements having a resonance characteristic of a secondfrequency, which is lower than the first frequency, disposed on thesubstrate, the plurality of first ultrasonic elements being arrangedalong a first direction to make a first high-frequency ultrasonicelement line to an n-th high-frequency ultrasonic element line (n is aninteger of more than 2), the plurality of second ultrasonic elementsbeing arranged along the first direction to make a first low-frequencyultrasonic element line to an n-th low-frequency ultrasonic elementline, the first high-frequency ultrasonic element line to the n-thhigh-frequency ultrasonic element line being arranged along a seconddirection which intersects with the first direction, the firstlow-frequency ultrasonic element line to the n-th low-frequencyultrasonic element line being arranged along the second direction, eachof the first ultrasonic elements and each of the second ultrasonicelements having an opening provided in the substrate, a vibratingmembrane that covers the opening, and a piezo element part provided onthe vibrating membrane, and a length in the second direction of theopening of each of the first ultrasonic elements being shorter than alength in the second direction of the opening of each of the secondultrasonic elements.
 2. The ultrasonic device according to claim 1,further comprising: a first high-frequency drive electrode wire to ann-th high-frequency drive electrode wire arranged along the firstdirection; a first low-frequency drive electrode wire to an n-thlow-frequency drive electrode wire arranged along the first direction;and a plurality of common electrode wires arranged along the seconddirection, a first electrode, which is placed in each of the pluralityof first ultrasonic elements configuring an i-th high-frequencyultrasonic element line (i is an integer of 1 or larger and n orsmaller) among the first high-frequency ultrasonic element line to then-th high-frequency ultrasonic element line, being connected to an i-thhigh-frequency drive electrode wire among the first high-frequency driveelectrode wire to the n-th high-frequency drive electrode wire, a secondelectrode, which is placed in each of the plurality of first ultrasonicelements configuring the i-th high-frequency ultrasonic element line,being connected to any one of the plurality of common electrode wires, athird electrode, which is placed in each of the plurality of secondultrasonic elements configuring a j-th low-frequency ultrasonic elementline (j is an integer of 1 or large and n or smaller) among the firstlow-frequency ultrasonic element line to the n-th low-frequencyultrasonic element line, being connected to a j-th low-frequency driveelectrode wire among the first low-frequency drive electrode wire to then-th low-frequency drive electrode wire, and a fourth electrode, whichis placed in each of the plurality of second ultrasonic elementsconfiguring the j-th low-frequency ultrasonic element line, beingconnected to any of the plurality of common electric wires.
 3. Theultrasonic device according to claim 2, wherein the piezo element parthas a lower electrode that is provided on the vibrating membrane, apiezoelectric body film is provided to cover at least a part of thelower electrode, an upper electrode is provided to cover at least a partof the piezoelectric body film, the first electrode is one of the upperelectrode and the lower electrode, and the second electrode is the otherof the upper electrode and the lower electrode.
 4. The ultrasonic deviceaccording to claim 1, wherein the first high-frequency ultrasonicelement line to the n-th high-frequency ultrasonic element line and thefirst low-frequency ultrasonic element line to the n-th low-frequencyultrasonic element line are alternately arranged along the seconddirection.
 5. An ultrasonic probe comprising the ultrasonic deviceaccording to claim
 1. 6. An ultrasonic diagnostic device comprising: theultrasonic device according to claim 1; the processing device configuredto perform processing of ultrasonic wave transmission to the ultrasonicdevice; and a display part configured to display image data for display.